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It hoped to find new oil wells, far away from the attacks of Nigeria's other major armed group, the Niger Delta Avengers, who are active further south.

But Boko Haram have once again shown that they pose a significant security threat and are not willing to be eclipsed just yet.

"It's clear that Boko Haram's strategy has evolved to more or less hit-and-run tactics and kidnapping people wherever they find them," Cheta Nwanze, an analyst with the Nigerian thinktank SBM Intelligence told RFI.

But he stopped short of saying the armed Islamists are trying to compete with the Niger Delta Avengers for control over oil.

"The attack took place because Boko Haram are in Borno State," he said. "The oil workers happened to be there like sitting ducks, they were out in the open and they were caught."

Army changes tactics

But Boko Haram has curtailed the NNPC's exploration activities in the Lake Chad Basin and for Nwanze "that's an admission that the area is not secure".

The high number of casualties proves that.

"Unlike in other recent attacks, the army actually went to mount a rescue operation, so there was a battle, that is what has caused the high death toll," says Nwanze. "For the other attacks, the army's strategy has been repel and defend, repel and defend, this time they actually went to seek out the attackers."

Is the army's strategy to blame?

"It's too soon to tell," he says. "If they had stuck with the old response then the terrorists would have taken their hostages and would have just disappeared. This time around at least some people were rescued."

Tuesday's high death toll will undoubtedly be a blow to the government, which has repeatedly insisted the Boko Haram insurgency was all but wiped out.

"People are thinking the army is not doing enough to protect the life of the people," said Aziz. "They need more reinforcements. They don't trust the government."

The government has since ordered its top army chiefs to relocate to Maiduguri and the Nigerian army has pledged to capture Boko Haram leader Abubakar Shekau within 40 days. It made a similar ultimatum last December.

And there is confusion surrounding the ambush itself.

It was initially thought to be a kidnapping attempt. Hostages were said to be rescued, before later being pronounced dead, and some members of the oil exploration team are still missing.

Locals want more from oil wealth

"People are saying that it is about high time for them to learn the game and come together to protect their culture and their wealth," added Aziz, echoing the desire of inhabitants to have greater autonomy over their oil wealth.

The government on Friday announced that local communities will be able to have ownership over their own oil resources, which could douse some of the anger that has fueled the rise of groups like the Niger Delta Avengers.

It could also send a positive message to oil producing countries within Opec.

"Don't forget that Nigeria and Libya have been exempted from the oil production quota agreement determined by Opec because of the insecurity affecting oil exploration and oil production," economist Laure Gnassou told RFI.

"It sends a positive message because it means that by one way or another the government is trying to address insecurity by including local communities."

Nigerian officials were contacted for this article but declined our interview request.